what percentage of stairwells really need the riser cleaned?
100 percent. Why?
1. Ive seen posts where they say "they dont look dirty". Well Ive cleaned plenty of carpet that at first didnt "look dirty" where in fact after cleaning made a big difference.
2. If you skip this step, it leads to skipping other steps too. After awhile your just like everyone else, so how do you differentiate from everyone else?
Just today I had a set of steps where the risers were bad. Took an upholstery bonnet to them and they looked like new. Thats the rare case tho.
But if you want to be a 2 percenter you better clean 100 percent and give 100 percent effort, 100 percent of the time.